Proportional valve

ABSTRACT

The invention relates to a proportional valve, especially for regulating the shifting pressure in an automatic transmission for a motor vehicle. The inventive valve is subdivided into a hydraulic section and into an electric section by a magnetic interface (XXXX). The bearing points ( 1, 2 ) of the hydraulic valve slide are arranged on the side of the valve opposite the electric coil, i.e. in the hydraulic section, so that the armature ( 5 ) projects into the coil space in a floating manner.

FIELD OF THE INVENTION

The present invention concerns a proportional valve, especially for theshifting pressure regulation in an automatic transmission for a motorvehicle.

BACKGROUND OF THE INVENTION

Proportional valves for the regulation of pressure are in manifold usagein automobile technology.

Pressure regulating valves, for example, are employed for the brakingcircuit for motor vehicles which are equipped with Anti-Blocking-System(ABS), as has been disclosed by DE 19715 024. In this cited patent, ashifting arrangement is described for the connection of currentconsuming equipment to an energy supply with emphasis given to ahydraulic pump and the electrically activated hydraulic valve of an ABScontrol arrangement for a motor vehicle. In this case, there is added,between the consuming equipment and the energy source, ON/OFF switchingof the pump for individual activation of the hydraulic valve and for atotal shutoff thereof.

Valves of the type used for the ABS-braking technology have beenconstructed also as digital valves, which have a magnetic interfaceavailable, so that a separation can be directly realized between thehydraulic and the electrical sections of the complete module in thedigital valve. This entails the advantage, that with highly integratedmodules, on the one hand separately testable units are made, and on theother hand by means of the high degree of integration, savings in costbecome possible. This subdivision into hydraulic and electrical sectionsof a complete module has, up to this time, exclusively been adaptablefor shift valve service, since, in this case, the manufacturingtolerances in the magnetic interface suffice to meet the requirements ofthe reproducibility of the magnetic flux.

SUMMARY OF THE INVENTION

The purpose of the present invention is to create a proportional valve,which, likewise, is divided by means of a magnetic interface into anelectrical section and into a hydraulic section and in which themagnetic flux exhibits a high degree of reproducibility.

Starting from a proportional valve of the type described more closely inthe introductory passages, the achievement of this purpose isaccomplished by the features given in Claim 1. Advantageous embodimentsare described in the subordinate claims.

Within the framework of the invention, provision has also been made,that the proportional valve, by means of a magnetic interface, isdivided into a hydraulic section and an electrical section, whereby thebearing surfaces of the hydraulic valve spool are located on that end ofthe valve remote from the electrical coil, that is, the bearing surfacesare placed in the hydraulic section, so that the armature remains freein the coil space.

The magnetic interface is comprised of, first, a meandering line in thecoil housing casing, which runs essentially perpendicular to the valveaxis, second, a cross-slotting producing a spring action, and third, thesaid interface exhibits the shape of a slide fit with a lengthytransition taper.

Advantageously, the electrical section is provided with knife edgecontacts and floats freely in a provided receiver with a bent shapedspring. The module possesses on its side which receives the electricalsection a disk spring for transmitting externally imposed, axiallydirected forces against the magnetic interface.

With the invented design of a proportional valve, which is particularlywell adapted for the shifting pressure regulation in automatictransmissions for motor vehicles, the advantage is achieved, that twoseparate, testable units have been made available, namely one being theelectrical section and the other being the hydraulic section. Theresponsibility for a testable mechanical/electronic complete module canthen be shifted to the suppliers. With the addition of furtherelectrical functions, placement of this proportional valve is possibleinto the transfer plate furnished in the automatic transmission. A costsavings can be made by the omission of more specialized components. Theintegrated, compact construction design makes possible, in addition, anoptimal use of installation space.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be described, by way of example, with referenceto the accompanying drawings in which:

FIG. 1 a longitudinal section through a proportional valve constructedin accord with the invention,

FIG. 2 a section through the detail in FIG. 1 designated with Z,

FIG. 3 a plan view on this detail of FIG. 1 marked by Z, and

FIG. 4 a section along the line A—A of FIG. 1.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 shows a section through the proportional valve of the inventeddesign, the said valve having an electrical section designated by“electric” and a hydraulic section marked “hydraulic”. In the case ofthe invented proportional valve these sections are provided to beseparable from one another, but are shown in FIG. 1 in the assembledcondition. In accord with the invention, in the case of thisproportional valve, there is provided for the armature an unencumberedplacement. That is to say, the bearing surfaces 1 and 2 of the hydraulicvalve spool 3 are placed on that end of the proportional valve which isremote from the electrical section. The bearing surfaces 1, 2 are thusin the hydraulic section so that the armature 5 rests freely into thecoil space.

The actual magnetic interface B, which divides to the two sections, onefrom the other, is essentially formed in the coil housing casing 6 andby means of a cross slotting 7 (FIG. 2) is springlike constructed. Thatis, it is constructed as a sliding fit with a long transition taper 8(FIG. 3). The magnetic interface B is indicated in FIG. 1 with acharacterizing line marked . . . xxx . . . . This interface B does notdivide the two sections from one another by one line running in oneplane, but takes a meandering course shown in FIG. 1.

The electrical section exhibits, advantageously, a knife contact 9,which, for example, is floatingly carried in a module 10 which serves toaccept the said electrical section by means of a bent shaped spring 11(FIG. 4), so that manufacturing tolerances, especially axismisalignments, can be compensated for. On the module side, there isfurther an integrated disk spring 12 which transmits externalsuperimposed, axial forces f onto the magnetic interface B.

Reference Numbers and Items

1 Bearing location

2 Bearing location

3 Hydraulic valve spool

4 Electrical coil

5 Armature

6 Housing casing

7 Cross slotting

8 Taper, conical

9 Knife-edge contact

10 Module

11 Bent shape spring

12 Disk spring

What is claimed is:
 1. A proportional valve, especially for the shiftingpressure regulation in an automatic transmission for a motor vehicle,with an electrical coil for generating a magnetic field and with anarmature, which is slidable in a space housing said coil and which isaxially connected to a hydraulic valve spool, wherein the proportionalvalve possesses an interface (B) designed with a springlike cross slot(7) and has the shape of a sliding fit seat with a lengthy transitioncone (8), the interface (B) divides the valve into a hydraulic sectionand an electrical section, wherein the bearing locations (1, 2) of thehydraulic valve spool (3) are found on that end of the valve remote fromthe electrical coil, that is found in a hydraulic section, so that thearmature (5) rests unencumbered in the coil space.
 2. The proportionalvalve according to claim 1, wherein the interface (B) comprises space inthe coil housing casing (6) running essentially perpendicular to thelongitudinal valve axis.
 3. The proportional valve according to claim 1,wherein the electrical section possesses knife blade contacts (9) and isfreely floating in a module (10) which is provided with a centeringspring (11).
 4. The proportional valve according to claim 1, wherein themodule (10), receiving the electrical section is provided with a diskspring (12) for the transmission of externally imposed connection forces(F) onto the interface(B).